decoder/encoder

def encode(text,shift):
    alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    encoded_message=''
    for letter in text:
        if letter in alphabet:
            index = alphabet.index(letter)
            new_index = (index + shift) % 52
            encoded_message += alphabet[new_index]
        else:
            encoded_message += letter

    return encoded_message


def decode(text,shift):
    alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    decoded_message=''
    for letter in text:
        if letter in alphabet:
            index = alphabet.index(letter)
            new_index = (index - shift) % 52
            decoded_message += alphabet[new_index]
        else:
            decoded_message += letter

    return decoded_message


text = "Hello World"
text = decode(text,3)

print(text)
print(encode(text,3))